1993 25HP Johnson J25TEETS, Carb Rebuild?

[Tucker99]

New to me boat, estate sale, last sticker registration is 04. Replace stat, plugs, plug wires, fuel pump, water pump, and set sync & link to spec, idle screw set 2-1/2 tuns out. Before tearing into carb, I would like the boards help diagnosing running problems. Motor is in test tank and starts, runs rough, won't idle low, and dumps fuel like crazy in the test tank. Seems to rev ok but low speed is very rough. Is this a case of a carb needing rebuild? Thanks guys...

 

[oldboat1]

You might first play around a little with the idle mix screw settings. Try for a leaner setting, 1/8 turn at a time clockwise, letting the motor adjust between changes. You also want to be sure the ignition output is strong. Get an open air adjustable spark tester, and look for about 1/2 inch strong spark on each lead. Compression test would be a good idea as well.

But you may end up doing a carb cleaning and kit installation. Be thorough.

Nice motor.

 

[Tucker99]

Thanks, I'm hoping it's going to be a nice motor. Just checked spark, 1/2" on each coil with the spark tester. I check compression in the parking lot when i bought the boat, engine cold, 113 lb each cyl. Yea, I had the slow speed setting wrong, reduced to 1-1/2 turns from 2-1/2 turns. Lot of loose dirt laying in the bottom of the cowling and I can see some of it in the carb. I ordered an OEM carb rebuild kit, but I'm sure I have something clogged. I'm ordering one of those carb cleaning kits. I think they're torch tip cleaners.

 

[flyingscott]

Look at the primer, either electrical or mechanical could be leaking.